Page 1 of 4 | © 2005-2010 text and photos by Michael Jacobi
The following article was written in late 2004 and published in the premiere issue of ARACHNOCULTURE in early 2005. At the time these methods were experimental, but since they proved successful in breeding Poecilotheria subfusca. The conditioning cage described herein was also successful in mating P. smithi, and the bred female appeared to be about to produce an eggsac, but this rare female met an unfortunate and untimely death soon after. She was the only female of this species in the author's collection. P. rufilata has been bred successfully using more traditional methods a number of times, as long as an appropriate cooling period is used for pre-breeding and post-breeding conditioning.
This article describes the housing and environmental conditions I am experimenting with to maintain my adult female Poecilotheria smithi and P. subfusca, two arboreal theraphosids found in the highlands of Sri Lanka's Central Province. It is a preliminary report since I have yet to breed either species using the methods detailed here. The difficulty that arachnoculturists including myself have had reproducing these two species has inspired me to try something very different than what has been successful in breeding other Poecilotheria.
At present, the genus Poecilotheria, a group of arboreal theraphosids endemic to India and Sri Lanka, consists of fourteen species — eight in India and six in Sri Lanka (Editor's Update: As of late 2009, there are presently 16 recognized species). These strikingly patterned spiders typically inhabit holes in dead or, in some cases, live trees or secrete themselves beneath tree bark and are often unseen until found in cut timber or illegally collected firewood. There has been a surge of interest in the captive husbandry of Poecilotheria, which arachnoculturists commonly refer to as "ornamental tarantulas" or "tiger spiders". The former popular name was coined in Andrew M. Smith's The Tarantula Classification and Identification Guide and was inspired by Reginald Innes Pocock's 1899 paper that described four new species of Poecilotheria where he wrote, "The upperside of the body and limbs is ornamented with blotches and stripes of brown and grey". This common name is much more widespread. The name "tiger spider" is used in India and Sri Lankan where local names may translate as tiger or leopard (e.g., the Hindi Pulna Salendy = tiger spider; the Singhalese Divimakuluwa = leopard spider [Andrew M. Smith, pers. comm.]). I personally favor the name "tiger spider" because of this link to local culture.
My special interest is the genus Poecilotheria, especially the species found at higher elevations: the Sri Lankan Poecilotheria smithi Kirk 1996 and P. subfusca Pocock 1895 and the Indian P. rufilata Pocock 1899. However, at this time I am only maintaining the Sri Lankan montane species in the manner reported here. P. rufilata is the Indian counterpart of the closely related P. subfusca. It is a dark tiger spider that lives in montane forests of southern India. It inhabits a higher elevation than P. smithi, but the captive breeding of P. rufilata has been much less problematic than that of either Sri Lankan mountain species and captive bred spiderlings are often available in the trade. At this time, I am housing my P. rufilata in more traditional arboreal tarantula cages like my other Poecilotheria, but place them at floor level so they are cooler (below 75°F [24°C]).
Smith et al. (2002) detailed the habitat of Poecilotheria subfusca with emphasis on the low temperatures found in the Central Highlands of Sri Lanka. This coolness was also noted by Kirk (1993). P. subfusca is a mountain spider found from Kandy south to Nuwara Eliya. Above the tea plantations of the hills lies secondary scrub forest and remnants of montane forest where this dark spider inhabits hole retreats in dead trees sometimes enveloped by fog. Even during the warmest months, February and March, temperatures rarely exceed 70°F [21°C] and during September the early morning hours may be as cool as 40°F [4°C] at elevations near 6500 ft [2000 m] where P. subfusca is found. Nuwara Eliya, a village within the range of P. subfusca, rests at 6168 ft [1880 m] above sea level and seven degrees north of the equator [6°58' N; 80°46' E]. A study of weather data recorded there over a number of years reveals average daily maximum temperatures of 65-71°F [18-22°C] and average daily minimums of 44-55°F [7-13°C]. In a nine year period the highest recorded temperature was 78°F [26°C] in March and the lowest was 27°F [-3°C] in January. Sri Lanka's precipitation is related to the Asiatic monsoons and there are two rainy seasons: April to June and October to November. During these periods average monthly rainfall at Nuwara Eliya is 10-12 in [250-300 mm]. However, the relative humidity remains high throughout the year, even during the driest months. Although the average monthly precipitation during February is only 1.7 in [43 mm], early morning humidity is still about 85% and late afternoon humidity averages 65%. Over the course of a year relative humidity at 0800 hours is 84-91% and at 1700 hours is 66-86%. During a lecture at the 2003 American Tarantula Society conference Andrew Smith commented on being able to see one's breath in the morning and fog rolling in during late afternoon where he has found P. subfusca.
Poecilotheria smithi is also from the highland interior of Sri Lanka, but is found at lower altitudes than P. subfusca. Its distribution is centered around the town of Kandy where it inhabits forests below 3000 ft [900 m].